One of the requirements for electrical cords and plugs used in life support equipment such as in hospitals is that the plug and cord assembly have a strength resisting separation which is equal to or greater than the strength of the electrical conductors. Until recently, the only assembly which met this requirement was an assembled plug. In copending application, Ser. No. 697,143 filed June 17, 1976, now U.S. Pat. No. 4,181,394, is disclosed and claimed a molded-on plastic plug body which utilizes a combination of strain relief members which have been found sufficient to achieve the aforementioned strength requirement.
Extensive testing of the aforementioned electrical cord and molded plug have revealed that a conventional ground pin blade can, under extraordinary abuse, fracture within the molded plug body. The conventional ground pin blade is a channel-shape member having the sidewalls of the portion of its length within the molded plastic body flatted to provide retention of the blade in the molded plastic body. Some failures of this plug have occurred under abusive and extraordinary treatment wherein the flatted portion of the channel blade fractured by fatigue failure, typically fracturing in the transition of the ground blade between its flat and channel portions.